1. Field of the Invention
This application relates to a system and method for controlling an engine to provide a vehicle operator with enhanced vehicle capabilities (e.g., the ability to manually exceed an established maximum vehicle speed normally imposed by the vehicles engine control) for a selected period of time, and a system for determining whether the engine control clock has been tampered with to prolong or extend any such enhanced capabilities.
2. Background Art
Vehicle engines, and particularly truck engines, are typically controlled by electronic engine control modules which implement various methods of controlling the vehicle engine to optimize the operation of the vehicle. For example, U.S. Pat. No. 5,477,827, assigned to Detroit Diesel Corporation, also the assignee of the present invention, discloses a system and method for controlling an engine including the capability of establishing a normal maximum speed and adding to that maximum speed for a selected time period as a driver performance incentive whenever the driver operates the vehicle within certain established performance goals, such as minimization of idle time, selection of the optimal transmission gear, maintaining a steady throttle, or reducing the use of engine driven accessory loads.
The capability of establishing a normal speed limit provides fleet managers and individual truck owners with the capability of insuring that their truck operators drive safely and meet desired fuel efficiency and other vehicle and engine operation goals. However, programming electronic engine control modules to establish vehicle speed limits which may, for example, maximize fuel efficiency, may otherwise limit the operator""s ability to operate the vehicle in an optimal fashion in an atypical situation, such as an emergency, or when it is desirable to safely pass other vehicles at a speed in excess of the established normal speed limit for the vehicle.
Because the goals of the vehicle owner or fleet manager (e.g, fuel efficiency, economy of operation) may at times conflict with the goals of the vehicle operator (e.g., minimizing time on the road), the operator may have incentive to defeat or tamper with the electronic engine control, such as by disconnecting or tampering with sensors, or changing the engine control""s clock.
It is therefore an object of the present invention to provide a system and method for controlling an engine which allows the manufacturer, fleet manager, or vehicle owner to establish a normal vehicle speed limit, but which also allows the vehicle operator to exceed that established speed limit to allow the operator to safely pass other vehicles, or otherwise operate the vehicle at a higher speed in an emergency.
It is also an object of the present invention to provide a system and method for controlling a vehicle engine which provides the operator the capability of manually operating the vehicle to exceed the established normal speed limit of the vehicle for a preselected time period, including warning the operator when the period during which the operator can manually override the vehicle speed limit is about to lapse.
It is also an object of the present invention to provide a system and method for controlling a vehicle engine which detects tampering with the engine control clock, and records any such tampering, and/or alters the engine control to reduce or eliminate the possibility of defeating programmed engine control restrictions.
It is also an object of the present invention to provide a system and method for controlling a vehicle engine which provides the operator the capability of manually operating the vehicle to exceed the normally established operational limits of the vehicle for a preselected time period, and for automatically reestablishing the preselected time period of enhanced operation at established intervals (e.g., every 24 hours), provided that no clock tampering has been detected.
In carrying out the above and other objects, the computer readable storage medium, control, and method of the present invention includes providing the operator with a particular operating capability for a time period which is reestablished at a predefined reset interval, periodically determining whether the system clock has been changed to a time which would prompt reinitialization of the time period during which the operator may utilize the particular capability and, if such a change has occurred logging a record of the tampering event and/or suspending any steps which would provide the capability to the operator for any additional time. In one embodiment, the present invention includes establishing a normal vehicle speed limit, establishing a passing duration period, establishing a passing override reset interval, and controlling the engine in response to operator input to provide a vehicle speed exceeding the normal vehicle speed limit for a cumulative passing period not greater than the passing duration period at any time during the passing override reset interval. If no system clock tampering has been detected, the passing duration period is re-established at the beginning of each reset interval (i.e., the operator is automatically provided with, for example, 30 minutes of speed limit override time during each 24-hour period). If clock tampering is detected, the system records the occurrence of the clock tampering. And, if tampering is detected, the system may also disable or delay the reinitialization of the passing duration period, so as to prevent the operator from obtaining additional enhanced driving capabilities by tapering with the clock.
When implemented on an electronic engine control module, the system, medium, and method of the present invention thus allows an operator to override the normal vehicle operation limits (such as the speed limit) imposed, for example, by the vehicle fleet manager, for a limited period of time to allow the vehicle operator to safely pass other vehicles. Moreover, if clock tampering is detected, the system and method of the present invention will record any such tampering on an event log, and may also eliminate the reinitialization of any enhanced driving capabilities to prevent the operator to benefit from such tampering.
These and other objects, features and advantages of the present invention are readily apparent from the following detailed description of the best mode for carrying out the invention when taken in connection with the accompanying drawings.